Optical disk recording and reproducing apparatus having faster reproducing speed than recording speed

Abstract

An optomagnetic disk recording and reproducing apparatus includes an optomagnetic disk having a vertical magnetic film capable of recording and reproducing an information signal, a recording and reproducing head unit for recording an information signal in the optomagnetic disk and reproducing an information signal recorded in the optomagnetic disk, a spindle motor for rotationally driving the optomagnetic disk, and means for controlling the spindle motor such that a rotational speed of the optomagnetic disk upon reproducing of an information signal recorded in the optomagnetic disk performed by the recording and reproducing head unit is set higher than the rotational speed of the optomagnetic disk upon recording of an information signal in the optomagnetic disk performed by the recording and reproducing head unit.

What is claimed is: 
     
       1. An optical disk recording and reproducing apparatus comprising: an optical disk having an optical recording medium capable of optically recording and reproducing an information signal;   recording and reproducing means for recording an information signal in said optical disk and reproducing an information signal recorded in said optical disk in a normal playback mode;   rotary driving means for rotationally driving said optical disk;   means for controlling said rotary driving means so that a rotational speed of said optical disk upon reproducing of an information signal recorded in said optical disk performed by said recording and reproducing means during the normal playback mode is higher than the rotational speed of said optical disk upon recording of an information signal in said optical disk by said recording and reproducing means; wherein said control means includes clock signal generating means for generating basic clock signals having different respective frequencies upon recorded and reproducing said optical disk by said recording and reproducing means and wherein said control means includes decoder means for detecting a frame sync signal from a detection output from said recording and reproducing means and forming a sync signal of a reproduced frame on the basis of the clock signal from said clock generating means.   
     
     
       2. An apparatus according to claim 1, wherein said clock signal generating means generates the basic clock signals such that a basic clock signal used for reproducing by said recording and reproducing means is of a higher frequency than a basic clock signal used for recording by said recording and reproducing means. 
     
     
       3. An apparatus according to claim 1, wherein said control means includes rotary driving control means for comparing phases of the frame sync signal and the reproduced frame sync signal and controlling said rotary driving means on the basis of this comparison output, and rotationally driving said rotary driving means on the basis of the clock signal from said clock generating means.